| Document and Entity Information | Oct. 29, 2020 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001682852 |
| Document Type | 8-K |
| Document Period End Date | Oct. 29, 2020 |
| Entity Registrant Name | MODERNA, INC. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-38753 |
| Entity Tax Identification Number | 81-3467528 |
| Entity Address, Address Line One | 200 Technology Square |
| Entity Address, City or Town | Cambridge |
| Entity Address, State or Province | MA |
| Entity Address, Postal Zip Code | 02139 |
| City Area Code | (617) |
| Local Phone Number | 714-6500 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common stock, par value $0.0001 per share |
| Trading Symbol | MRNA |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
