What Estonia actually asks for
The Estonian requirement is short. The Ministry of Foreign Affairs page for the long-stay D visa, the route the digital nomad visa runs on, asks for travel medical insurance "which guarantees payment of any costs related to applicant's medical treatment due to applicant's illness or injury during the validity of the visa", and adds that as a rule it must be valid for the whole period of the requested visa. The Police and Border Guard Board says the same thing in its own words: a valid insurance contract ensuring payment of treatment costs incurred through illness or injury of the applicant for the period of validity of the visa being applied for.
Two things follow. Travel medical insurance is the named category, which means the products sold to nomads are the right shape rather than the wrong one. And the test is temporal: the contract must span the visa. Nothing in either page requires the insurer to be Estonian, registered locally, or connected to Estonia in any way.
The 30,000 euro figure is not an Estonian rule
Every guide to this visa states a minimum of 30,000 euros. The ministry page gives no figure. The border guard page gives no figure. The outsourced visa centre one-pager for Estonian D visas repeats the ministry wording and gives no figure either. What exists is the Schengen Visa Code threshold of 30,000 euros, which governs short-stay C visas throughout the area, and which gets carried across to long-stay applications by habit and by the insurers selling Schengen-compliant policies.
The honest position is this: buy a policy with a limit well above 30,000 euros, because a low limit invites a question and because 30,000 euros is thin cover for a serious hospital stay anywhere in Europe, but do not believe anyone who tells you Estonia publishes that number. It does not, at least not on the pages an applicant is directed to.
No local insurer rule, but there is a list
Estonia does not do what Spain does. There is no equivalent of the Spanish requirement that the policy come from an entity authorised to operate in the country, and there is no line anywhere saying travel insurance is invalid. A foreign nomad policy is legally fine.
What Estonia has instead is softer and worth knowing. The Police and Border Guard Board is commonly cited as accepting a handful of named providers, ERGO, Inges, Salva Kindlustus, and the broker KindlustusEst, and Estonian insurers sell products aimed specifically at foreigners applying for or extending a visa or residence permit. The advantage of buying one is not legal, it is administrative: the officer reading your file has seen the document before. ERGO's contract can be signed after arrival in Estonia and Salva's can be signed online from abroad, which covers both the apply-from-home and extend-in-country cases.
You will not get into the public system
The most expensive assumption about Estonia is that a country famous for digital government will let a digital nomad into its health service. It will not, and the reason is structural rather than hostile. The digital nomad visa is a visa. It is not a residence permit and it creates no residence.
Estonian public cover through Tervisekassa follows Estonian employment or board-member fees with the 33 percent social tax paid on them, subject to a monthly minimum base. Someone employed by a foreign company and paid abroad triggers none of that. There is a related carve-out on the ministry page, stating that where Estonian health insurance will start after arrival the travel policy only has to bridge the gap, but it is written for people taking Estonian jobs. Digital nomads do not qualify for it, and reading it as an invitation to buy three months of cover for a twelve-month visa is a refusal waiting to happen.
The practical consequence is that your private policy is not a paperwork item. For up to a year it is the only thing standing between you and Estonian private hospital pricing. Buy on cover, not on the cheapest document that satisfies an officer.
e-Residency is not residency, and it carries no cover
Estonia's best-known export to the nomad world is e-Residency, and it confuses this topic more than any other single thing. An e-Residency card is a digital identity that lets you register and run an Estonian company and sign documents remotely. It is not a residence permit, it is not a visa, it does not let you live in Estonia, and it creates no health cover of any kind, anywhere.
People arrive at the insurance question having already got an e-Residency card and assume some part of the Estonian state is now looking after them. Nothing is. If you hold e-Residency and want to spend a year in Tallinn, you still apply for the digital nomad visa on the terms above, and you still buy a private policy for the whole visa period.
The one connection worth drawing is on the company side. If your Estonian company pays you a salary or a board-member fee and the 33 percent social tax goes with it, that is the route into Tervisekassa, and it is a tax and structuring decision rather than an insurance one. Take advice before choosing it, because the social tax will dwarf any private premium you were trying to avoid.
What to buy
For most applicants the answer is a full-year nomad travel medical policy bought as a single block, with a certificate in English showing your name, the start and end dates and the insured sum. Nomad plans in this category run roughly 50 to 70 US dollars per four-week period for a healthy applicant under 40, and international health insurance costs several times that with much better cover for anything ongoing.
If you want to remove all doubt, buy from one of the Estonian insurers the border guard is used to seeing. It is not required and it will often cost more than a nomad plan, but for an applicant who is already stretching on the 4,500 euro monthly income evidence, a clean file is worth something.
Practical sequence
Decide the visa length first, C for up to 90 days or D for up to 12 months, then buy insurance that covers exactly that period rather than your loose travel plans. Gather six months of income documentation showing size, regularity and source, since the border guard asks for it explicitly. Get the insurance certificate in English with dates and insured sum on the face of it. Assume you will never touch Tervisekassa, and price the policy as real healthcare rather than as a form. The visa page covers the income test and the difference between the visa and Estonian residence.