TK or AOK for students: TK is a single nationwide fund with one additional contribution (Zusatzbeitrag), whereas AOK consists of eleven legally independent regional funds, each with its own rate. The question is therefore not TK against AOK but TK against the AOK of your region. This guide shows the range across the regional AOKs and makes no recommendation.
Short answer: TK charges an additional contribution of 2.69 percent. According to the fund list of the GKV-Spitzenverband (as of 27 October 2026), the eleven regional AOKs range from 2.47 to 3.50 percent. On a contribution base of 855 euros, compared with TK that is a range from minus 1.88 euros to plus 6.93 euros per month.
The key points
- The AOK group has no uniform additional contribution. It depends on the regional AOK.
- AOK Bayern sits at 2.69 percent, the same as TK, AOK Rheinland-Pfalz/Saarland below it and AOK Nordost at the upper end.
- AOK determines which regional AOK is responsible for you by postcode, and offers differ by region.
- For students, AOK names offices near the campus at many universities, but the page gives no list of locations.
- General rules on contribution and switching are in the guide student health insurance in Germany 2026: key figures.
How widely do the regional AOKs’ additional contributions vary?
The table compares each regional AOK with TK. The difference refers to the monthly amount for students on a contribution base of 855 euros. All rates come from the fund list of the GKV-Spitzenverband dated 27 October 2026.
| Regional AOK | Additional contribution | Monthly amount | Difference to TK (23.00 euros) |
|---|---|---|---|
| AOK Rheinland-Pfalz/Saarland | 2.47 percent | 21.12 euros | minus 1.88 euros |
| AOK Bayern | 2.69 percent | 23.00 euros | 0.00 euros |
| AOK Sachsen-Anhalt | 2.89 percent | 24.71 euros | plus 1.71 euros |
| AOK Hessen | 2.98 percent | 25.48 euros | plus 2.48 euros |
| AOK Niedersachsen | 2.98 percent | 25.48 euros | plus 2.48 euros |
| AOK NordWest | 2.99 percent | 25.56 euros | plus 2.57 euros |
| AOK Baden-Württemberg | 2.99 percent | 25.56 euros | plus 2.57 euros |
| AOK PLUS | 3.10 percent | 26.51 euros | plus 3.51 euros |
| AOK Rheinland/Hamburg | 3.29 percent | 28.13 euros | plus 5.13 euros |
| AOK Bremen/Bremerhaven | 3.29 percent | 28.13 euros | plus 5.13 euros |
| AOK Nordost | 3.50 percent | 29.93 euros | plus 6.93 euros |
Worked example: between the AOK with the lowest rate and the one with the highest there are 8.81 euros per month, or 105.68 euros over twelve months. The example shows the spread within the AOK family, not the cost of a particular fund. For you only the rate of the AOK responsible at your home or study location counts.
Which AOK is responsible for you?
AOK’s student page points out that offers vary by region and that the responsible AOK is determined by postcode. If your home and your place of study are in different federal states, this is not a side issue: ask in writing before joining which regional AOK will accept you and what rate it charges. There are separate guides on the individual regional funds, such as AOK student health insurance: regional rates 2026.
How do service and extras differ?
| Topic | AOK (student page) | TK |
|---|---|---|
| Points of contact | Offices near the campus at many universities, no list of locations according to AOK | One nationwide fund, points of contact not listed on the pages reviewed |
| Digital | Meine AOK with online portal and app, request certificates | TK app, TK-Doc for medical advice by smartphone |
| Proof of insurance | Automatic transmission to the university, paper proof for universities abroad | Not covered by the pages reviewed |
| Courses and seminars | Yoga and relaxation courses and AOK-liveonline seminars on study stress and time management with no personal contribution | Bonus programme with challenges, subsidy for prevention courses under the articles |
| Phone | Varies by region | Service team 040 460 660, around the clock |
Frequently asked questions
Can I join an AOK in another federal state?
That depends on which regional AOK is responsible for you. AOK assigns by postcode. Clarify special cases, such as a residence in a different state from your place of study, directly with AOK and have the answer confirmed in writing. TK, by contrast, is the same fund with the same rate for all students nationwide.
Is the student contribution rate different at AOK?
No. The rate of 10.22 percent on 855 euros applies at every statutory fund (as of 1 January 2026). Only the additional contribution differs, and each regional AOK sets it individually.
Does AOK offer a bonus for students?
AOK Nordost names a StarterBonus for career starters, trainees and students with premiums of up to 935 euros per year (page updated 17 March 2025), tied to income limits and proofs by 31 March of the following year. Whether your regional AOK offers something similar is something to ask there.
How long am I bound after switching?
Twelve months, unless the additional contribution rises. The rules are in switching health insurer as a student.
Next steps
- Find out by postcode which regional AOK is responsible for you.
- Look up its rate in the fund list of the GKV-Spitzenverband and compare it with TK’s 2.69 percent.
- Ask about the office and bonus offers in your region.
- Decide and have your admission confirmed in writing.
Related reading
- AOK student health insurance: regional rates 2026
- TK student health insurance: costs and benefits 2026
- Additional contribution 2026: all health insurers
- German health insurance terms for newcomers
Sources: GKV-Spitzenverband, health insurance fund list (27 October 2026, German), AOK, benefits for students (retrieved October 2026, German), AOK Nordost, StarterBonus (updated 17 March 2025, German), GKV-Spitzenverband, fact sheet on contribution calculation values (1 January 2026, German).
Last updated: October 2026. This guide is general information, not individual advice.
